Add metrics to measure time elapsed between form load and form submission with or without Autofill.

BUG=none
TEST=unit_tests --gtest_filter=AutofillMetricsTest.*

Review URL: http://codereview.chromium.org/7740070

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@99447 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/ipc/ipc_message_utils.h b/ipc/ipc_message_utils.h
index e7bbe34..7c46f90 100644
--- a/ipc/ipc_message_utils.h
+++ b/ipc/ipc_message_utils.h
@@ -105,6 +105,7 @@
 class ListValue;
 class Time;
 class TimeDelta;
+class TimeTicks;
 struct FileDescriptor;
 }
 
@@ -332,6 +333,14 @@
   static void Log(const param_type& p, std::string* l);
 };
 
+template <>
+struct IPC_EXPORT ParamTraits<base::TimeTicks> {
+  typedef base::TimeTicks param_type;
+  static void Write(Message* m, const param_type& p);
+  static bool Read(const Message* m, void** iter, param_type* r);
+  static void Log(const param_type& p, std::string* l);
+};
+
 #if defined(OS_WIN)
 template <>
 struct ParamTraits<LOGFONT> {